Audio mixer



FIG. 1 is a front, top and side perspective view of a audio mixer, embodying our new design;

FIG. 2 is a rear, top and side perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a side elevational view of one side thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a rear elevational view thereof.

The broken lines shown are included for the purpose of illustrating the unclaimed portions of the article and form no part of the claim. 

The ornamental design for an audio mixer, as shown and described. 